environments
What reason (other than perhaps being easier for my syntax highlighter to parse) is there to write
\begin{center}
Here is centered text
\end{center}
rather than:
\center
Here is centered text
\endcenter
And likewise for other environments. Does the \begin do any extra funky checks or are they effectively synonymous?
As noted in comments the standard minipage and lrbox environments are designed for this use, or for the particular case of framing a box, mdframed package.
To note why the definition shown does not work, you can not delimit macro arguments with \begingroup.
\fbox \begingroup
is the same as
\fbox{\begingroup}
and passes the \begingroup token as the content of the box. After that things are bound to go wrong.
Similarly
\parbox{10cm} \begingroup
is
\parbox{10cm}{\begingroup}
with \begingroup being passed as the argument to \parbox.
This uses an environment - wrapper, via \NewDocumentCommand from xparse package for possible better configurability (and \par content as argument values).
Possible vertical spacing issues are not addressed.
It's however not possible to say \mytheorem{Title} content ... since the environment needs a clear end.
\documentclass{article}
\usepackage{xparse}
\usepackage{amsthm}
\newtheorem{theorem}{Theorem}[section]
\renewcommand{\thetheorem}{\arabic{theorem}}
\NewDocumentCommand{\mytheorem}{+m+m}{%
\begin{theorem}{#1}
#2
\end{theorem}
}
\begin{document}
\section{First}
\mytheorem{Theory on Brontosaurs, by Miss Ann Elk}{%
Brontosaurs are thin at one end, thick in the middle and thin again at the other end.
}
\end{document}
Edit: Update ... a 'generic' wrapper command for such theorem environments
This defines a generic wrapper command for such newtheorem issues:
\GenericWrapper[section]{theoremname}{Theoremname} will generate a command \mytheoremname with is wrapper for \begin{theoremname}...\end{theoremname} and reset every section (default value of the optional 1st. argument). (xparse is used with \NewDocumentCommand for this, in order to facilitate the usage of optional arguments in contrast to the \newcommand[][] way.)
The command changes the theorem label to \arabic{theoremname}.
\documentclass{article}
\usepackage{xparse}
\usepackage{amsthm}
\NewDocumentCommand{\GenerateWrapper}{+O{section}+m+m}{%
\newtheorem{#2}{#3}[#1]
\expandafter\renewcommand\csname the#2\endcsname{\arabic{#2}}%
\expandafter\DeclareDocumentCommand\csname my#2\endcsname{+m}{%
\begin{#2}%
##1%
\end{#2}
}%
}%
\GenerateWrapper{theorem}{Theorem}%
\GenerateWrapper{exercise}{Exercise}%
\GenerateWrapper{question}{Question}%
\begin{document}
\section{First}
\mytheorem{%
Theory on Brontosaurs, by Miss Ann Elk%
Brontosaurs are thin at one end, thick in the middle and thin again at the other end.
}%
\myexercise{Find a Brontosaur%
Excavate a Brontosaur
}%
\myquestion{Mathematics
Prove that
\[ \int\limits_{-\pi}^{\pi} e^{-x^2} = \sqrt{\pi} \]
}%
\end{document}
Best Answer
\beginand\endbuild a group, which can keep settings local. Simply writing\command ... \endcommanddoesn't. Such a scope is very important for me, that's why I prefer the\begin ... \endsyntax.Example: